um: take register_winch_irq() into the caller of is_skas_winch()

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

arch/um/drivers/chan_user.c

@@ -281,7 +281,12 @@ void register_winch(int fd, struct tty_struct *tty)
 		return;
 
 	pid = tcgetpgrp(fd);
-	if (!is_skas_winch(pid, fd, tty) && (pid == -1)) {
+	if (is_skas_winch(pid, fd, tty)) {
+		register_winch_irq(-1, fd, -1, tty, 0);
+		return;
+	}
+
+	if (pid == -1) {
 		thread = winch_tramp(fd, tty, &thread_fd, &stack);
 		if (thread < 0)
 			return;

arch/um/os-Linux/skas/process.c

@@ -26,11 +26,7 @@
 
 int is_skas_winch(int pid, int fd, void *data)
 {
-	if (pid != getpgrp())
-		return 0;
-
-	register_winch_irq(-1, fd, -1, data, 0);
-	return 1;
+	return pid == getpgrp();
 }
 
 static int ptrace_dump_regs(int pid)